Investigation of antimicrobial resistance and antimicrobial resistance genes in Staphylococcus aureus and coagulase-negative staphylococci isolated from rabbit.

Background and Aim: Staphylococci, which inhabit skin and mucous membranes in humans and animals, are opportunistic pathogens. Coagulase-positive and coagulase-negative staphylococci (CoNS) are the two main groups. Clinical abscesses in rabbits often harbor Staphylococcus aureus and CoNS. This study estimated S. aureus and CoNS prevalence, resistance profiles, antimicrobial-resistant genes, and the accessory gene regulator (agr) group in rabbit clinical abscesses. Materials and Methods: Sixty-seven abscesses were gathered from 67 rabbits who visited Prasu-Arthorn Animal Hospital in Nakornpathom, Thailand, from January 2014 to October 2015. Thirty-four subcutaneous, 29 dental, 2 ocular, 1 mammary gland, and 1 uterine abscess were present. Conventional methods, including Gram staining, mannitol fermentation, hemolysis on blood agar, catalase testing, and coagulase production, identified and isolated S. aureus and CoNS from all abscesses. All S. aureus and CoNS isolates underwent antimicrobial susceptibility testing using the disk diffusion method. Polymerase chain reaction was used to detect the presence of blaZ, aacA-aphD, msrA, tetK, gyrA, grlA, dfrG, and cfr antimicrobial-resistant genes. Methicillin resistance was identified through the detection of a cefoxitin-resistant phenotype and the presence of mecA gene. Further investigation was conducted on the agr group of S. aureus isolates. Results: In 67 abscesses, we found 19 S. aureus isolates in 9 abscesses (13.43%) and 37 CoNS isolates in 18 abscesses (26.87%), both majorly located at subcutaneous sites. About 59.46% of CoNS isolates were methicillin-resistant compared to 5.26% of S. aureus isolates. Methicillin-resistant S. aureus (MRSA) and methicillin-resistant CoNS (MRCoNS) both displayed multidrug resistance (MDR). Both MRSA and MRCoNS expressed multiple antimicrobial resistance genes, including blaZ, aacA-aphD, gyrA, grlA, msrA, tetK, and dfrG. Approximately 73.68% of the agr groups were agr I, 15.79% were agr III, and 10.53% were agr II. Conclusion: This study found a high prevalence of MRCoNS with antimicrobial resistance and multiple antimicrobial-resistant genes in rabbits with clinical abscesses. The effectiveness of antibiotics against infections caused by such strains is a matter of concern. Owners should be educated about the importance of good hygiene practices and judicious antibiotic use to prevent widespread antimicrobial resistance.

Distribution of sequence types and antimicrobial resistance of clinical Pseudomonas aeruginosa isolates from dogs and cats visiting a veterinary teaching hospital in Thailand.

BACKGROUND: Pseudomonas aeruginosa is an important opportunistic pathogen in dogs and cats and is resistant to several antimicrobial drugs; however, data on the clonal distribution of P. aeruginosa in veterinary hospital are limited. This study aimed to investigate the clonal dissemination and antimicrobial resistance of clinical P. aeruginosa in a veterinary teaching hospital in Thailand within a 1-year period. Minimum inhibitory concentration determination and whole genome sequencing were used for antimicrobial susceptibility analysis and genetic determination, respectively. RESULTS: Forty-nine P. aeruginosa were isolated mostly from the skin, urinary tract, and ear canal of 39 dogs and 10 cats. These isolates belonged to 39 sequence types (STs) that included 9 strains of high-risk clones of ST235 (n = 2), ST244 (n = 2), ST274 (n = 2), ST277 (n = 1), ST308 (n = 1), and ST357 (n = 1). Overall antimicrobial resistance rate was low (< 25%), and no colistin-resistant strains were found. Two carbapenem-resistant strains belonging to ST235 and ST3405 were identified. CONCLUSIONS: Clinical P. aeruginosa in dogs and cats represent STs diversity. High-risk clones and carbapenem-resistant strains are a public health concern. Nevertheless, this study was limited by a small number of isolates. Continuous monitoring is needed, particularly in large-scale settings with high numbers of P. aeruginosa, to restrict bacterial transfer from companion animal to humans in a veterinary hospital.

Occurrence of antimicrobial resistance and antimicrobial resistance genes in methicillin-resistant Staphylococcus aureus isolated from healthy rabbits.

Background and Aim: Methicillin-resistant globally, Staphylococcus aureus (MRSA) is a major cause of disease in both humans and animals. Several studies have documented the presence of MRSA in healthy and infected animals. However, there is less information on MRSA occurrence in exotic pets, especially healthy rabbits. This study aimed to look into the antimicrobial resistance profile, hidden antimicrobial-resistant genes in isolated bacteria, and to estimate prevalence of MRSA in healthy rabbits. Materials and Methods: Two-hundreds and eighteen samples, including 42 eyes, 44 ears, 44 oral, 44 ventral thoracic, and 44 perineal swabs, were taken from 44 healthy rabbits that visited the Prasu-Arthorn Animal Hospital, in Nakornpathom, Thailand, from January 2015 to March 2016. The traditional methods of Gram stain, mannitol fermentation, hemolysis on blood agar, catalase test, and coagulase production were used to confirm the presence of Staphylococcus aureus in all specimens. All bacterial isolates were determined by antimicrobial susceptibility test by the disk diffusion method. The polymerase chain reaction was used to identify the antimicrobial-resistant genes (blaZ, mecA, aacA-aphD, msrA, tetK, gyrA, grlA, and dfrG) in isolates of MRSA with a cefoxitin-resistant phenotype. Results: From 218 specimens, 185 S. aureus were isolated, with the majority of these being found in the oral cavity (29.73%) and ventral thoracic area (22.7%), respectively. Forty-seven (25.41%) MRSAs were found in S. aureus isolates, with the majority of these being found in the perineum (16, 34.04%) and ventral thoracic area (13, 27.66%) specimens. Among MRSAs, 29 (61.7%) isolates were multidrug-resistant (MDR) strains. Most of MRSA isolates were resistant to penicillin (100%), followed by ceftriaxone (44.68%) and azithromycin (44.68%). In addition, these bacteria contained the most drug-resistance genes, blaZ (47.83%), followed by gyrA (36.17%) and tetK (23.4%). Conclusion: This study revealed that MRSA could be found even in healthy rabbits. Some MRSAs strains were MDR-MRSA, which means that when an infection occurs, the available antibiotics were not effective in treating it. To prevent the spread of MDR-MRSA from pets to owners, it may be helpful to educate owners about effective prevention and hygiene measures.

Staphylococcus argenteus from rabbits in Thailand.

Staphylococcus argenteus, a novel species of the genus Staphylococcus or a member of the S. aureus complex, is closely related to S. aureus and is usually misidentified. In this study, the presence of S. argenteus in isolated S. aureus was investigated in 67 rabbits with abscess lesions during 2014-2016. Among 19 S. aureus complex isolates, three were confirmed to be S. argenteus by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, nonribosomal peptide synthetase gene amplification, and multilocus sequence type. All S. aureus complex isolates, including the S. aureus isolates, were examined for their antimicrobial resistance phenotype by disk diffusion and for their resistance genotype by PCR assays. Among the S. argenteus isolates, one was susceptible to all antimicrobial drugs and the other two were resistant to penicillin and doxycycline. In contrast, most S. aureus isolates were resistant to penicillin (37.5%), and gentamicin (12.5%). Moreover, S. aureus isolates harbored the blaZ, mecA, aacA-aphD, and mrs(A) as well as mutations of gyrA and grlA, but S. argenteus isolates carried solely the blaZ. S. argenteus isolates were investigated for enterotoxin (sea-sed) and virulence genes by PCR. One isolate carried sea, sec, and sed, whereas the other two isolates carried only sea or sed. No isolate carried seb and see. All three S. argenteus isolates carried hla, hlb, and clfA, followed by pvl, whereas coa, spa (IgG-binding region), and spa (x region) were not detected in the three isolates. This paper presents the first identification of S. argenteus from rabbits in Thailand. S. argenteus might be pathogenic because the isolates carried virulence genes. Moreover, antimicrobial resistance was observed. Investigations of this new bacterial species should be conducted in other animal species as well as in humans.

Prediction of cadmium (Cd) toxicity in cattle.

Hepato- and nephrotoxicity can be induced by the exposure to cadmium (Cd). This toxicity can be detected by the elevation of blood biomarkers such as ALT AST, ALP BUN and creatinine. These elevations are found in small animals, e.g. mice and rats. However the alteration of biomarkers did not investigate in large animals, e.g. cattle. Hepato- and nephrotoxicity induced by cadmium can also be examined by the alterations of metallothionein (MT) and metal transcription factor-1 (MTF-1). To present study the expressions of these markers, the cattle were classified into five groups according to the levels of cadmium in the kidneys. ALT, AST andALP were analyzed to determine liver damage whereas BUN and creatinine were examined for kidney damage. The results showed that blood biomarkers were not sensitive enough to be correlated markers to cadmium induced hepato- and nephrotoxicity in cattle. The expressions of MT and MTF-1 protein were investigated by immunofluorescence method. The expressions of MT and MTF-1 proteins were firstly found in the cattle group which had low cadmium concentration in tissues (< 0.5 mg/kg). Thus, these proteins could be used as the sensitive markers to determine the cadmium exposure. The MT and MTF-1 gene expressions were also studied. However, there was no correlation between the level of RNA and the protein expressions due to the concentration of protein levels bearing unclear relationship with the mRNA level. The investigation of these protein expressions is very useful because the result can be used as a protective method to prevent consumption of cadmium-contaminated beef.

The reality of osteocalcin as a marker of vitamin K2.

The present study showed the correlation between undercarboxylated osteocalcin and vitamin D had a role in production of the undercarboxylated osteocalcin, when the amount of vitamin D 25 (OH) D, (below 30 ng/ml) was decreased, the linear correlation (r) between the vitamin D and undercarboxylated osteocalcin were also decreased r = 0.032 when the level of vitamin D was risen, the linear correlation was 0.274,unfortunately the study-population had little group of the normal level of vitamin D due to most of them were vitamin D insufficiency so the authors could not show the more value of 'r'. However, the present study confirmed that the role of vitamin D information of undercarboxylated osteocalcin (UcOC) which we recognized the UcOC at the low level of vitamin D will misinterpretation of the level of vitamin K2.

Correlation between the circulating bone markers and vitamin D in the healthy Thai people.

There are several circulating bone markers that are useful for physicians in determining the bone quality. The markers are composed of N-terminal propeptide of type I collagen (PINP) which determines the bone formation, undercarboxylated osteocalcin (UcOC) and N-mid fragment of osteocalcin (N-MID) which determines the bone remodeling, C-telopeptide of type I collagen (betaPCTx) or betacrosslap (betaCTx), pyridinoline (PYD) and deoxypyridinoline (DPD) which determines the bone resorption. The vitamin named vitamin D (VitD) also affects the bone property. However there is little information about the relationship of these biomarkers. In this experiment, the researchers investigated the correlation of the circulating biomarkers and found the correlations between UcOC and betaCTx (r = 0.471, p = 0.011), between UcOC and Vit D (r = 0.39, p = 0.04), between N-MID and PINP (r = 0.833, p = 0.000), between N-MID and PCTx (r = 0.641, p = 0.000) and lastly between PINP and betaCTx (r = 0.657, p = 0.000) in the male group whereas the correlations between UcOC and PYD (r = 0.318, p = 0.043), between UcOC and DPD (r = 0.551, p = 0.008), between N-MID and PINP (r = 0.721, p = 0.000), between N-MID and PCTx (r = 0.719, p = 0.000), between N-MID and PYD (r = 0.485, p = 0.001), between N-MID and Vit D (r = 0.347, p = 0.026), between PINP and JCTx (r = 0.632, p = 0.000), between PINP and PYD (r = 0.312, p = 0.047), between bCTx and PYD (r = 0.365, p = 0.019), between PYD and DPD (r = 0.567, p = 0.006) and lastly between PYD and Vit D (r = 0.409, p = 0.008) were found in the females. In addition, the new biomolecule named matrix Gla protein (MGP), a small protein produced by bone tissues was also investigated. The authors found the correlation between MGP and PYD (r = 0.468, p = 0.012) in the males and found the correlations between UcOC and MGP (r = 0.421, p = 0.006), between N-MID and MGP (r = 0.333, p = 0.033), between MGP and PYD (r = 0.471, p = 0.002), between MGP and DPD (r = 0.472, p = 0.026) in the female group.

Bone markers in the healthy Thai people.

Osteoporosis is a systemic skeletal disease characterized by low bone mineral density (BMD) and micro-architectural deterioration of the bone tissues resulting in bone fragility and susceptibility to fracture. It is caused by the decrease of bone formation and the increase of bone resorption. Both bone formation and resorption can be examined by the circulating biomolecules. The biomolecules using in determining the bone formation are composed of osteocalcin (OC) in form of N-terminal midmolecule fragment (N-MID) and undercarboxylated osteocalcin (UcOC). The other bone formation markers are matrix Gla protein (MGP) and N-terminal propeptide of Type I collagen (PINP) whereas the biomolecules using in determining the bone resorption comprises of C-terminal cross-linking telopeptide of Type I collagen (betaCTx), collagen cross-links molecules which are pyridinoline (PYD) and deoxypyridinoline (DPD). Nevertheless, some vitamins such as vitamin D (Vit D) and some hormones e.g. parathyroid hormone (PTH) are also affected to the bone quality. To monitor and assess the bone mass, the normal values of bone markers as well as the relevant biomolecules are important and should be established. The researchers aimed to investigate the normal values of the interesting bone biomarkers and the relevant biomolecules in the adult volunteers.

Investigation of sensitive biomarkers to determine cadmium inducing hepato- and nephro-toxicity in cattle by immunofluorescence method.

Cadmium inducing hepato- and nephro-toxicity can cause the alteration of protein expression such as metallothionein (MT), i.e. cadmium binding protein, and the metal transcription factor-1 (MTF-1), which plays a significant role in cellular responses to the heavy metal stress. To study the expression of these proteins, the cattle were classified into five groups resulting from the levels of cadmium in the kidneys. Next, the blood biochemical profiles were analyzed to estimate the liver and kidney functions. The expressions of MT and MTF-1 proteins both in the liver and kidneys were investigated by immunofluorescence method. This study found that the blood biochemical profiles were not correlated with the level of cadmium in these tissues; however, the expressions of MT and MTF-1 proteins were earlier detected in the bovine which had a low level of cadmium contamination (0.5 mg/kg). Thus, these proteins could be used as the sensitive markers to determine the cadmium in tissue.